@lilmagi You're right about the usage of shoujo-ai being synonymous to lolicon in Japan (I apologise because I wasn't aware until just now), but considering that we are discussing things in English I was mainly referring to how the phrases are used in the west, and it's not 'new fans' and mangadex, this phrased has been used since over a decade ago. It is relatively new if you compare it to when it first started to be used in Japan.
But isn't it similar to how the word 'Hentai' became synonymous to Anime Porn in the west, or how 'Doujin' is used to commonly refer to Manga Porn. The word 'Shoujo Ai' and 'Shounen Ai' have been widely misused and perpetuated in the community way before batoto and mangadex appeared.
If you go to the Japanese Wikipedia https://ja.wikipedia.org/wiki/%E5%B0%91%E5%A5%B3%E6%84%9B
On Shoujo-Ai there's a section that says even in Japan there have been occasions where it's been used to refer to Yuri-related works, but it also says that the term is widely used in the west. You can probably take this as another case of cultural appropriation?